There are two universally applicable techniques for reading
hands in all poker games and one more for open-handed games
like seven-card stud, razz, and hold 'em. Most commonly you
analyze the meaning of an opponent's check, bet, or raise,
and in open-handed games you look at his exposed cards and
try to judge from them what his entire hand might be. You
then combine the plays he has made throughout the hand with
his exposed cards and come to a determination about his most
likely hand.

Here is a simple problem in reading hands that should make
this point clear. The games is seven-card stud, and your opponents
are decent players :

Player A with
the pair of aces showing bets; Player B with the pair of kings
showing calls; and Player C with the pair of queens showing
calls. There are no raises. You are last to act. How should
you play your three 7s?

If you combine what you see on board with what your opponents
have done, there should be no doubt in your mind that you
must fold; your three 7s have no chance whatsoever. The crucial
factor is that the pair of queens overcalled. Player A may
be betting with aces alone. But when Player B calls him, Player
B must have at least kings up. Being a decent player, Player
C knows this. Therefore, C could not call without having kings
up beat. What are C's possible hands? Well, C cannot have
aces and queens or kings and queens because there's a third
ace and a third king out, making it impossible for C to have
two of either. So, he must have three queens or better, and
while your three 7s might beat the first two hands, they cannot
beat C's three queens or better. Therefore, you fold.

Here is a good example of this kind of hand reading, which
to my chagrin cost me half a pot. I was playing five-card
stud high-low split with a replace on the end. With an ace
and an 8 showing, I called the maximum raises on third street
even though two other players each had a 6 and a 5 showing.
There was another player in the pot with an obvious pair of
kings. When it got down to the last card, I had A,8,6,3 showing.
One 6,5 had folded, but despite the strength of my board,
the other stayed with a ragged 6,5,10,Q showing. And of course,
the pair of kings stayed. Now I was betting and raising, hoping
the Q, l O low would get out. But that player read me too
well. He didn't even take the opportunity to replace one of
his cards.

What I was trying to do was win the whole pot, the high and
the low, from the two kings, but the Q, l O low was clever
enough to figure out my hand. He said to himself, "Sklansky
is representing an 8 low, but could he have an 8 low? No,
he couldn't. Why? Because he would never have called all those
raises on third street with three cards to an 81ow when there
were two other players in the pot who looked as if they had
three cards to a 6 low. Therefore, he must have another ace
in the hole." He was, of course, absolutely right. I
won the high with my two aces, beating the two kings, but
the Q,10 low was rewarded for his accurate reading with the
low half of the pot (which I would have won against the two
kings with my two aces counting also as a low pair). The player
with the Q,10 low considered the way I played the hand not
just at the end, but from the beginning, and he combined my
play with the cards showing to arrive at the correct conclusion
about what I was holding. He also analyzed the order in which
I received my up cards. He knew I started with A,8 and then
caught the 6 and the 3. If he had not known that - if, for
example, he had not been sure whether I started with A,8 or
A,6 - it would have been impossible for him to conclude with
such certainty that I had a pair of aces.

It is in this way that you use logic to read hands. You interpret
your opponents' plays on each round, and in open-handed games
you note the cards they catch on each round, paying close
attention to the order in which they catch them. You then
put these two pieces of evidence together - the plays and
the up cards - to draw a conclusion about an opponent's most
likely hand.

In that high-low split hand, the Q, l O low was able to put
me on a specific hand quite early. However, it is generally
a mistake to put someone on a specific hand early and then
stick to your initial conclusion no matter how things develop.
A player who raises on third street in seven-card stud with
a king showing may have two kings, but he may also have a
small pair in the hole with the king kicker or a three-flush
or a J,Q,K or a number of other hands as well. Drawing a narrow,
irreversible conclusion early can lead to costly mistakes
later, either because you fold with the best hand or because
you stay in as a big underdog.